Ventricular–arterial coupling: Invasive and non-invasive assessment

Interactions between the left ventricle (LV) and the arterial system, (ventricular–arterial coupling) are key determinants of cardiovascular function. Ventricular–arterial coupling is most frequently assessed in the pressure–volume plane using the ratio of effective arterial elastance (E_A) to LV end-systolic elastance (E_ES). E_A (usually interpreted as a lumped index of arterial load) can be computed as end-systolic pressure/stroke volume, whereas E_ES (a load-independent measure of LV chamber systolic stiffness and contractility) is ideally assessed invasively using data from a family of pressure–volume loops obtained during an acute preload alteration. Single-beat methods have also been proposed, allowing for non-invasive estimations of E_ES using simple echocardiographic measurements. The E_A/E_ES ratio is useful because it provides information regarding the operating mechanical efficiency and performance of the ventricular–arterial system. However, it should be recognized that analyses in the pressure–volume plane have several limitations and that “ventricular–arterial coupling” encompasses multiple physiologic aspects, many of which are not captured in the pressure–volume plane. Therefore, additional assessments provide important incremental physiologic information about the cardiovascular system and should be more widely used. In particular, it should be recognized that: (1) comprehensive analyses of arterial load are important because E_A poorly characterizes pulsatile LV load and does not depend exclusively on arterial properties; (2) The systolic loading sequence, an important aspect of ventricular–arterial coupling, is neglected by pressure–volume analyses, and can profoundly impact LV function, remodeling and progression to heart failure. This brief review summarizes methods for the assessment of ventricular–arterial interactions, as discussed at the Artery 12 meeting (October 2012).     

Injection Drug Use and HIV Antiretroviral Therapy Discontinuation in A Canadian Setting

We investigated whether drug-related behaviors predicted antiretroviral therapy (ART) discontinuation among a cohort of injection drug users (IDU) in a Canadian setting. Cox regression analyses were used to investigate the impact of drug use patterns on rates of ART discontinuation among a sample of HIV-positive IDU in Vancouver, Canada between May 1996 and April 2008. In total, 408 HIV-positive IDU initiated ART during the study period, among whom 257 (63.0%) discontinued ART at least once. Rates of ART discontinuation were not significantly elevated among those who reported ongoing injection of heroin, cocaine, or other illicit drugs in comparison to those who reported not injecting drugs. However, public drug use was significantly predictive of ART discontinuation. Our findings may contribute to a reconsideration of the role of active drug use in determining retention in ART programs among IDU.     

Guiding-catheter thrombectomy combined with distal protection during primary percutaneous coronary intervention of a saphenous vein graft

Primary percutaneous intervention of saphenous vein grafts is associated with a high risk of distal embolization and no reflow. We report a case of acute myocardial infarction with a large intragraft thrombus, successfully treated with a technique combining thrombectomy with a 6 Fr guiding catheter and distal protection with the FilterWire EZ.     

Valor pronóstico a largo plazo del análisis completo de los índices de resonancia magnética cardiaca tras un infarto de miocardio con elevación del segmento ST

Introduction and objectives

A variety of cardiac magnetic resonance indexes predict mid-term prognosis in ST-segment elevation myocardial infarction patients. The extent of transmural necrosis permits simple and accurate prediction of systolic recovery. However, its long-term prognostic value beyond a comprehensive clinical and cardiac magnetic resonance evaluation is unknown. We hypothesized that a simple semiquantitative assessment of the extent of transmural necrosis is the best resonance index to predict long-term outcome soon after a first ST-segment elevation myocardial infarction.

Methods

One week after a first ST-segment elevation myocardial infarction we carried out a comprehensive quantification of several resonance parameters in 206 consecutive patients. A semiquantitative assessment (altered number of segments in the 17-segment model) of edema, baseline and post-dobutamine wall motion abnormalities, first pass perfusion, microvascular obstruction, and the extent of transmural necrosis was also performed.

Results

During follow-up (median 51 months), 29 patients suffered a major adverse cardiac event (8 cardiac deaths, 11 nonfatal myocardial infarctions, and 10 readmissions for heart failure). Major cardiac events were associated with more severely altered quantitative and semiquantitative resonance indexes. After a comprehensive multivariate adjustment, the extent of transmural necrosis was the only resonance index independently related to the major cardiac event rate (hazard ratio=1.34 [1.19-1.51] per each additional segment displaying >50% transmural necrosis, P<.001).

Conclusions

A simple and non-time consuming semiquantitative analysis of the extent of transmural necrosis is the most powerful cardiac magnetic resonance index to predict long-term outcome soon after a first ST-segment elevation myocardial infarction.Full English text available from: www.revespcardiol.org/en     

Angiotensinogen Promoter Polymorphisms Predict Low Diffusing Capacity in U.S. and Spanish IPF Cohorts

Background

Single nucleotide polymorphisms (SNPs) in angiotensinogen (AGT) at positions ?20 and ?6 are associated with increased severity and progression of various fibrotic diseases. Our earlier work demonstrated that the progression of idiopathic pulmonary fibrosis (IPF) was associated with the A-6 allele. This study examined the hypothesis that the homozygous CC genotype at ?20 and the AA genotype at ?6 would confer worse measures of pulmonary function (measured by pulmonary function tests) in IPF.

Methods

Multiple logistic regression analysis was applied to a NIH Lung Tissue Research Consortium cohort and a Spanish cohort, while also adjusting for covariates to determine the effects of these SNPs on measures of pulmonary function.

Results

Analysis demonstrated that the CC genotype at ?20 was strongly associated with reduced diffusing capacity in males in both cohorts (p = 0.0028 for LTRC and p = 0.017 for the Spanish cohort). In females, the AA genotype was significantly associated with lower FVC (p = 0.0082) and V _alv (p = 0.022). In males, the haplotype CA at ?20 and ?6 in AGT was also strongly associated with reduced diffusing capacity in both cohorts.

Conclusions

This study is the first to demonstrate an association of AGT polymorphisms (?20A > C and ?6G > A) with lower measures of pulmonary function in IPF. It is also the first to relate the effect of gender in lung fibrosis with polymorphisms in AGT.     

Influence of smoking habits and CARD15 mutations on the onset of Crohn's disease

Objective. Coeliac disease (CD), an autoimmune gluten-dependent enteropathy, can be associated with several extra-intestinal manifestations, including neurological disorders. At present, no data are available on the presence of hearing loss disorder in coeliac patients. The aim of the present study was to investigate the prevalence of hearing loss in coeliac patients compared with that in healthy controls. Material and methods. Twenty-four adult coeliac patients and 24 healthy subjects matched for gender, age, smoking and drinking habits were enrolled in the study. Among the coeliac patients, 6 were newly diagnosed and 18 patients were on a gluten-free diet for at least one year. Results. A hearing loss was found in 10 (47.1%) coeliac patients and 2 (9.1%) healthy controls. All CD patients with hearing loss presented a sensorineural hearing loss. The prevalence of hearing loss was significantly higher in coeliac patients than in healthy controls (p=0.01) but it was not significantly different between untreated (33.3%) and treated (44.4%) coeliac patients (p: NS). Conclusions. Despite the low number of subjects evaluated, the present study showed a higher prevalence of hearing loss in coeliac patients than in healthy controls, suggesting an association between CD and hearing loss. Immunological processes such as ear-specific and non-specific autoantibodies and vasculitis could be the basis of this association. Further longitudinal investigations on a larger sample size will be necessary to confirm the present data.